High-throughput genome screening technologies, such as microarrays, SAGE, and proteomics have made it possible to survey thousands of genes/proteins at a time from tissue and cell preparations. The translation of such information to contribute to our understanding of basic biologic processes or to improve diagnostic, prognostic and therapeutic applications in the clinic requires extensive validation. Hundreds of experimental and/or clinical specimens are typically required to ascertain the significance of a gene or protein when one studies a biologic phenomenon or when developing a new diagnostic test or therapeutic target. This is often tedious with conventional technologies, and availability of such tissue resources is often rate limiting. Tissue microarrays provide a means for rapid, large-scale analysis of several hundred tissue specimens with hundreds of probes. Tissue microarrays are constructed by acquiring cylindrical biopsies from hundreds of individual tissues into a tissue microarray block, which is then sliced into over 200 sections for probing DNA, RNA or protein targets. A single immunostaining or in situ hybridization reaction can provide information on all of the specimens on the slide, while subsequent sections can be analyzed with other probes or antibodies. Taken together, the new discovery science based tools, in conjunction with tissue microarrays, provide a powerful approach for the in vivo validation of gene discoveries, as well as a means to rapidly assess the biologic and/or clinical significance of a given gene(s). Presently, the University of Chicago has a manual tissue arrayer. However, this type of fabrication is time and labor intensive. As such, we are presently unable to fulfill the large number of requests for their fabrication by the large number of NIH funded investigators who are seeking them. An automated tissue arrayer from Beecher Instruments would provide us with the ability to meet our investigators' needs. The instrument would be fully integrated into an existing core under the highly qualified supervision of Dr. Maria Tetriakova, Research Program Coordinator for the Department of Pathology. An already established Internal Advisory Committee will oversee an equitable and appropriate use by a broad disciplinary group of scientists while giving priority to NIH-supported groups.